Vim 8.1 release

Update version number and information.  Fix a couple of tests.
diff --git a/runtime/doc/scroll.txt b/runtime/doc/scroll.txt
index 653e7ed..971fec8 100644
--- a/runtime/doc/scroll.txt
+++ b/runtime/doc/scroll.txt
@@ -1,4 +1,4 @@
-*scroll.txt*    For Vim version 8.0.  Last change: 2018 Apr 26
+*scroll.txt*    For Vim version 8.1.  Last change: 2018 Apr 26
 
 
 		  VIM REFERENCE MANUAL    by Bram Moolenaar